This invention relates to an electric remote control system adapted for controlling one or more operating conditions of a marine propulsion unit, and more particularly to an improved remote control unit of such a system which includes a rotatable operator wherein the frictional force applied to the operator increases as the angle of rotation of the operator is increased beyond a preset angle from the neutral position.
One type of remote control system has been proposed which is employed on certain watercraft to actuate a throttle and/or transmission control lever on an associated marine propulsion unit. With this type of system, movement of an operator of the remote control unit results in an electrical signal being transmitted from the unit and which is used to control an actuator assembly that is mechanically connected to control lever(s) on the propulsion unit.
Because this type of electric remote control system does not require the use of a mechanical cable between the remote operator and the actuator assembly, the load that is normally imposed on the operator by the cable and the attached actuator assembly is eliminated thereby greatly reducing the overall load on the operator. A relatively light load on the operator is desireable in that it makes the shifting and/or throttle operation easier. However, it is necessary that the operator have some resistance to its rotation to insure proper operation. Therefore, it has usually been the practice in an electric remote control system to impose some load on the operator to provide this resistance and to insure proper operation. Typically, however, this applied load has been constant without regard to the degree of rotation of the operator and therefore without relation to the speed of the watercraft. As a result, movement of the operator tends to feel the same to the driver no matter what its position or how fast the watercraft is moving so that there is no operating feeling in the system. This tends to make operation of the watercraft somewhat uninteresting.
It is, therefore, a principal object of this invention to provide an improved electric remote control system for a marine propulsion unit which provides resistance against movement of a remote control operator that is related to the angle of rotation of the operator.
It is another object of this invention to provide an improved electric remote control system wherein the force required to move a remote operator of the system varies with the angular rotation of the operator to improve the operating feeling of the system.